Preoperative platelet count in predicting lymph node metastasis and prognosis in patients with non-small cell lung cancer

Recent studies have shown an indirect link between platelet count and blood vessel metastasis, but this association with lymphatic vessels metastasis has not been established in NSCLC. So we investigated whether an association exists between preoperative platelet count and lymph node metastasis in NSCLC patients. Between January 2001 and January 2011, platelet counts were obtained from 883 NSCLC patients who were resistant to chemotherapy, radiotherapy, and surgery. The preoperative platelet counts, tumor metastasis, and overall survival of NSCLC patients were analyzed for correlations via statistical analysis. Upon considering patients according to their TNM lymph node metastasis stage (N0-N3), multiple comparison analyses revealed that the mean preoperative platelet count of the NO group was significantly lower than that of the N1-N3. Analysis of variance showed that the preoperative platelet count of patients in stage I was significantly lower than that of those in stages II, III, and IV, with no significant difference among the latter three stages. According to the Kaplan-Meier survival analysis, the overall survival of patients with platelet counts <214.5 x 10(9)/L was significantly longer than that of those with platelet counts >= 214.5 x 10(9)/L. Cox regression analysis indicated that, besides preoperative platelet count, patient age, gender, and TNM stage were independent prognostic factors. In conclusion, preoperative platelet count was significantly associated with metastasis of lymph nodes in NSCLC patients. Preoperative platelet count may be a reliable biomarker of lymph node metastasis possibility and an independent prognostic factor of overall survival in patients with NSCLC.